This invention relates to a method and apparatus for identification of individuals, but more particularly to a method and apparatus for confirming the identity of an individual by the scanning of the fingerprint of the individual""s finger.
The use of an electronic representation of fingerprints for identification purposes has increased substantially in the last few years. This increase is due mainly to the improvements and miniaturizations made in the field of optics and electronics.
Fingerprints are, for example, used in high security establishments for providing or denying access to secured areas. For example, access to certain rooms or areas requiring high levels of security, may require fingerprint identification. Also, with the recent increase in credit card fraud, some credit card suppliers have experimented with intelligent credit cards, wherein fingerprints are used to authenticate the user of the card. An optical fingerprint reader is used during the credit card scanning process to determine whether the individual using the card is the authorized user of the card.
The need for fingerprint identification and authentication has required increasingly accurate fingerprint scanning devices. In some instances, ultrasonic wave and laser scanning techniques have been used to create holographic or 3-dimensional representations of the fingerprint. Some scanners also make use of special concave scanning surfaces and other scanning techniques to better recreate the scanned image of the fingerprint.
A problem associated with obtaining an accurate representation of a fingerprint is the amount of memory required to store the optical data obtained in the scanning process. Even though that information can generally be stored on a card, the amount of memory required to store sample fingerprints of each user of a banking machine of, say, only one banking institution, would simply be too large to store at each banking machine. For example, if a good monochromatic image is described by 1000xc3x971000 pixels and if each pixel is quantized to 256 levels of gray, then 8 million bits will be required to store or transmit such an image. It would take 8 bits per pixel to code the gray-level values of the image.
Another problem associated with the use or storage of fingerprints is with regards to maintaining confidentiality of the stored information. The extreme accuracy provided by some of these scanners has even been criticized. In some cases, objections on privacy grounds have been raised. For example, there is a perception that the use of the data containing an exact replicate of ones fingerprint might be improperly used by a third party.
This concern or fear amongst user groups has of course limited or delayed the introduction of fingerprint scanners or authentication devices for general public use.
Accordingly, there exist a need for an authentication device which can make use of the uniqueness provided by a fingerprint, but wherein the information necessary to authenticate the fingerprint is insufficient to reconstruct or duplicate the entire fingerprint.
It is therefore an object of the present invention to provide an authentication device which can confirm the identity of an individual by using a limited amount of information contained in a fingerprint.
Another object of the present invention is to provide an authentication device in which the information necessary to authenticate the fingerprint is insufficient to reconstruct or duplicate the entire fingerprint.
Another object of the present invention is to minimize the storage required to memorize the information obtained from the scanning of the fingerprint.
According to a first aspect of the invention, there is provided an apparatus for confirming the identity of an individual by the automatic scanning of a fingerprint. It is comprised of a scanning device for scanning the finger print of the individual""s finger so as to create an optical pattern of the finger print of said finger. A conversion circuit is used for converting the optical pattern to an electrical signal and an A/D converter is used for converting the analog electrical signal to digital information. The digital information is comprised of n bytes of digital information. A processor is used for receiving the n bytes of digital information and for selecting a number y of byte sequences, each byte sequence having m bytes, wherein the product of mxc3x97y less than n. A memory stores the selected byte sequences, such that when the correct byte sequence is detected out of said y byte sequences, authenticity of said individual is determined.
According to another aspect of the invention, there is provided a method confirming the identity of an individual, by scanning the fingerprint of the individual. As a first step, a scanning surface, adapted to receive the finger of said individual, is scanned in order to form an optical pattern representative of the contact area between the finger print of said finger and said scanning surface. Then, the optical pattern is converted to an electrical signal and the electrical signal is converted to n bytes of digital information. Once the n-bytes of digital information are received at a processor, a number y of byte sequences are selected. Each byte sequence has m bytes, wherein the product of mxc3x97y less than n. A memory containing byte sequences representative of fingerprints of a number of individuals requiring authentication is accessed and a comparison is done to determine whether the byte sequences selected by the processor and the byte sequences stored in the memory are the same, such that authenticity of said individual can be determined.